The research has as its objective the solution of two related problems: (1) the nature of the biochemical events involved in the synthesis of protein by animal cells (especially the structure and function of ribosomes); and (2) the mechanism whereby insulin (and other hormones) participte in the regulation of protein synthesis -- it follows, as a corollary, that we wish to gain an understanding of the character of the defect in protein metabolism that occurs in diabetic animals. We plan during the coming year to carry out the following studies: (1) A comparison of the proteins of N and D ribosomes by two- dimensional polyacrylamide gel electrophoresis. (2) A comparison of the phosphorylation of N and D ribosomal proteins in vivo and a study of the phosphorylation of N and D ribosomes in vitro by a protein kinase that uses ATP as phosphoryl donor and by enzymes that transfer the phosphoryl group of GTP. (3) We shall continue our effort to isolate, purify and characterize the 70 proteins of eukaryotic ribosomes preparatory to a comparison of the proteins of N and D ribosomes. (4) Development of techniques for determining the specific activity of the amino acids that are actually the precursors for protein synthesis. There is circumstantial evidence for separate amino acid pools in a number of cell types; there is also evidence that the amino acids used to synthesize protein come from a small rapidly-exchanging pool; and finally that insulin affects transport of amino acids into that pool. We wish to test the possibility that N and D muscle have different pools of amino acids.